EMBDEN – The state will spend $3 million to upgrade its trout and salmon hatchery on Embden Pond, tripling its fish production and transforming it into the largest in the state.

The hatchery will be shut down for a year beginning in June 2004 while the work is done, said Steve Wilson, the state’s superintendent of hatcheries.

“This is a very important hatchery, as far as the quality of fish we can raise from it,” he said. “We know we can really increase the potential of that facility. It’s worth the investment.”

Maine voters last fall approved a $7 million bond issue to upgrade and update six of the state’s nine aging fish hatcheries, most built in the 1950s and 1960s. The Embden hatchery is 50 years old.

The state has hired Fish Pro, an engineering and scientific firm from Springfield, Ill., to oversee the improvements.

The Embden facility now produces about 200,000 fingerlings, or 30,000 pounds of fish. After the improvements, the figure probably will increase to about 90,000 pounds, Wilson said.